Sliding vane pumps are known and are well suited to a variety of pumping applications due to their reliability and relatively few moving parts. However, the sliding vanes of such pumps are prone to sticking leading to decreased pump efficiency. This is particularly true at pump startup and when the internal components of the pump have been fouled by contaminants from the fluid being pumped. Accordingly, there is a need for a simple and reliable means to prevent and/or eliminate sticking or freezing of the vanes within a sliding vane pump.